Process of making formates.



UNITED s'IA'rns PATENT OFFIOE.

JULIUS WEISE, FRIEDRICH Innonn, AN'D ADOLF BARTH, or" 'OESTRICH' YON-THEJRHINE, GERMANY, ASSIGNORS T0 T e FIRM 0F RUDOLPH KOEPP & 00., or STRrGn-ON-THE-RHINE, GERMANY.

masses or MAKING Fonmm'ss. 3

lie. 820,159. r

' Speciflcstiono! Letters Patent.

Eatentod my s, 1900.

alkalies, whereby the process is expedited in an extraordinary manner and rendered ractical, valuable, and useful, while it yie ds a good output, which hitherto has never been attained. '7

Before proceeding to describe our inven tion we may first state a few facts in order to show the value'and importance of our inven-. tion. I V

The synthesis of formates from carbon monoxid 11nd caustic alkalieshas been investigated by Berthelot, {see Annales de Chemicet de P e, Srie 3, Vol. 46, 2856 page 480,- and rie 3, Vol. 61 1861, page lfiilfi bi; Merz and Tibirica (see'Berichte de'r Deutec en and by Goldschmidt. Berthelot first 'stated that he had obtained but a few per cont.,of

formate from merely moistened solid caustic alkali at a temperature of 100 centigrade after seventy hours and at. s ternnersture of 220 centi ado after ten hours. When (3) crating wit an aqueous solution at the or inary temperathre, he was able to ascertain an "'gnificant absorptionwithin four months. Later on Berthelot stated that he had made other ex enments while employing a rather remarka' le quantity of water of ordinary temgera'ture and that he succeeded in absorbmgn small quantity of carbon monoxid within six weeks while using a. large excess of alkali. When employing water-of 100 centigrade, he obtained the same cant result after from eighty to one undred hours. From his statements that he used alkalies in the solid state,that he used firs (merely moistene alkalies afterward a rather remarkable quantity oi water" in opposition to an aqueous solution? it is quite evident that the rather remarkable quantity of water did not mean at all a solution of alkali. Be it as it may, Berthalot was no doubt the first who recognized the Ohemischen Gesellschcft, XIII, pnge 23} im ortance of the water for the reaction and 5 5 lei stress on the same. However, Bertholot did not go further, and he did not even succeed in so'conclucting his experiments as to obtain a result of practi al importance, 'so that his result presented but a theoretical interest. Moreover, it was he himself who at the conclusion of his essay pronounced synthesis of formates to be a typical exampl i; of a slow reaction, and he therefore reconf'si I mendedto s thesize the formats from oxalic, acid and after a lmown method. More and irica e ually found the method of Berthelot to be 9. factors of the formats, and they attempted to impi-ove u on this method. However,

they went in t e wrong direction, as they emplayed the alkali exclusively in its solid stete thst is, without the use of water-and attho most the moisten'ed'th gast. 2., the v carbon monoxi a little. Goldschmidt went further and showed that the moist gas did I not 'eld a larger output than d' gas.

Vaiihave found that Berthelot modes 7 V steein the right direction, for water is very essential for procuring the reaction; How ever, according to our ex erirnsnts it will not do to merely moisten t e alkali or even to employ a rather remarkable quantity of Wfltor. t is absolutely necessary to employ such a large quantity of water as to form solntions of alkalies, so that slkalies in their solid state are no longer used. Ten er cent.

of water should be at least employ and it is preferable to employ considerably more water, At the same time we have found go that this quantity of water alone will not do for attaining the result aimed at According to our experiments it is absolutely nee to emplo the proper'temgersture, which 1s essential y higher than "300 centigrade.

The carbon meson i the extraordinary roperty of dissolving m'water at an increas Ing rate as the temperature increases (side the essa of Gerh. Just in Zeitschniftfiir phys'ikolise e Ghemic,Vol.37,page 342.) Thore fore it is evidently best to exceed the boilingpoint of the solution in use, the more so since with a solution of alkali no decomposition of the formed formate under the action of the higher temperature need be apprehended, as hitherto in the hithertoknown methods. Of course care should be taken to prevent the water from evaporating during t for a profitable manu'e 'stated above.

the reaction. In other words, the solution should be boiled within a closed vessel, the minimum pressure in the vessel being in accordance with the degree of concentration of the l e and the temperature. We havefurther ound that a third condition must be fulfilled-via, to bring the two agents into intimate contact with each other. Now that the two agents are a gas and a liquid it is of course evident that the desired intimate mixture can be easlly effected with the aid of known technical means, such as stirring de-, vices, nozzles, enlarged contact-faces, &c.

Our invention consists of a process presentin the three features named above, where y ft is rendered valuable, practical, and useful. It may be that the three fea tures have severally been partly described or made ublic, yet the combination of the three f datures is novel, and our improved process roduces an unexpected and sur rismg resu tvi'z., the reaction, which by erthelot was pronounced to be a t pically slow reaction, is now extraordinarii y expedited and rendered smooth, and the output is so large that it has never been anticipated heretofore.

. Our process consists in makingv an aqueous solution of a caustic alkali, heatlng the solution to 8. hi h tem eraturerin a closed vessel, preferably ieyon the boilin -point of'the solution, and in admitting car 11 monoxid and causing the two agents to act u on each other while under a itationor in a ely-divided condition. T e alkali in this case may be assumed to be caustic soda, while other alkalies and agents will be treated in other patent applications about to be filed.

The rapidity of the reaction increases pro portional y to the temperature, while the concentration exercises no great influence if sufficient .water be present. The operation mustbe carried out in closed vessels to prevent the water from evaporatin as. already The closed vesse s may be of any known and a proved construction. The heating of these 0 osed vessels ma be effects ed in any known manner. In or er that the operation may take place rapid] 'it is furt er necessary that the liquid an gas should be in intimate contact, for which purpose any suitable known device can be used. For instance, the liquidanay be atomized b stirring devices or n'ozz ,s, or it may be distribut'ed in 'thinla ers, a d the as may be blown into the vesse in a finelyivided state.

The'new improved met d may be carried out in various manners. elow we give two exf les. n

:Exarnple I: Soda-lyeat40 Baum is allowedto trickle onto coke in a closed vessel atfa temperature of 200 centigrade, and carbon monoxid (which preferably has been pre-' viously heated in any known manner) is pumped into the vessel from below in a direction op osite to that of the trickling lye. The car on monoxid is so rapidly absorbed by the lye that one might think it to be carbonic acid. When pro erly ca ing out the process, the soda-lye leaving t e vessel or tower will be found to have been turned 'into a solution of formt'ite. The latter may be used without an further treatment or be converted into soli formate.

' Example II: Sodarlye at 15 Baum is passed t rough a horizontal vessel at a temperature of 185 centigrade and therein atomized by means of an agitator, while the heated carbon monoxid is forced into the vessel in a direction 0 posits to that of the l e. Then the same bri ant'result is obtained as before. If insteadof pure carbon monoxid a mixture of the latter .with other gases may be used, these latter gases are blown off during the operation through a convenient valve:

The process ac'cordi resents' the following a vantages over those 'therto known: The reaction occurs most rapidly and as no decom osition can take lace the yieldis practice ly that indicated y theory. While in a previous rocess it was essential in order to exclude water to deprive the bases of water to grind them and mix them with large amounts of an inert substance, these lengthy and costly manipulations are done away with. The troublesome heating of large quantities of dry powder, which conducts heat badly and resents great difficulties in heating 1S rep seed by the much easier heating of a. liquid. Overheating and decomposition of the formate already formed is prevented. The final product need not, as in the previous processes, be lixiviated and does not contain an-additional-ine substance.

' What we claim as our invention, and desire to secure by Letters Patent, is

l. .The herein-described process of manufacturing formates, which consists in making an aqueous solution of an alkali, heating the aqueous solution to a high'temp'erature in a closed vessel admitting thereto carbon monoxid and by agitation causing the two agents to act upon each other.

2. The herein-described process of manufacturing formates, which 0 nsists in making an aqueous solution of an alkali, heating the aqueous solution to a temperature above the boiling-point in a closed vessel, admitting thereto carbon monoxid, and' by a 'tation causing the two agents to act upon eac other. In testimony whereof we have signed our names to this spe'cificationin the presence of two subscribing witnesses.

- JULIUS FRIEDRICH RIEOHE.

ADOLF BARTH. Witnesses:

Fns vz HABSLACHER, Eawm. DIPPEL.

IIO 

